US3832590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High pressure metal-vapor discharge lamp having alumina tube with thickened end portions sealed by alumina disks
Assignee: Panasonic Holdings Corp
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Filing: 1973-03-02
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Granted: 1974-08-27
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Expires: 1993-03-02
Abstract
Abstract A high-pressure metal-vapor discharge tube having improved characteristics is disclosed. The tube has an alumina hollow discharge enclosure tube member, the ends of which are sealed by alumina end disks. The end disks have central apertures through which electrode lead in wires or rods extend into the discharge enclosure. The lead in wires or rods are made of a material which is resistant to the corrosive effects of metal halide. The hollow discharge enclosure tube member has walls which are thicker at the two ends than in the intermediate region of the tube member. Preferably, the ends are more than twice as thick as the central walls. This results in a stronger seal between the alumina end disks and the tube member, thus not only avoiding the risk of breakage when sealing the tube member and manufacturing defects such as a defective seal, but also ensuring longer life of the lamp.
Inventors
- 👤 H Yamazaki
- 👤 H Akutsu
- 👤 T Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:31
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/36; H01J61/361
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
146 words
In a high pressure metal vapor discharge tube including a sealed tubular enclosure constructed of alumina, a pair of electrodes, one of said pair of electrodes disposed adjacent each end of said tubular enclosure, mercury and at least one metal halide being vaporized in operation of said discharge tube, the improvement which comprises: said alumina tubular enclosure having a wall thickness at the ends thereof greater than the wall thickness of the intermediate portion of said tubular enclosure, and a pair of alumina end disks bonded to the respective ends of said tubular enclosure for sealing thereof, said end disks having a higher modulus of rupture than said tubular enclosure and said end disks each having an aperture therein, and a wire selected from the group consisting of tungsten and molybdenum extending through each aperture and coupled to said electrodes for holding said electrodes in position.
Claim 2
Dependent Claim
146 words
In a high pressure metal vapor discharge tube including a sealed tubular enclosure constructed of alumina, a pair of electrodes, one of said pair of electrodes disposed adjacent each end of said tubular enclosure, mercury and at least one metal halide being vaporized in operation of said discharge tube, the improvement which comprises: said alumina tubular enclosure having a wall thickness at the ends thereof greater than the wall thickness of the intermediate portion of said tubular enclosure, and a pair of alumina end disks bonded to the respective ends of said tubular enclosure for sealing thereof, said end disks having a higher modulus of rupture than said tubular enclosure and said end disks each having an aperture therein, and a wire selected from the group consisting of tungsten and molybdenum extending through each aperture and coupled to said electrodes for holding said electrodes in position.
Claim 3
Dependent Claim
39 words
The improved high pressure metal vapor discharge tube of claim 1 wherein the wall thickness of said alumina tubular enclosure at the ends thereof is greater than twice the wall thickness of the intermediate portion of the tubular enclosure.
Claim 4
Dependent Claim
26 words
The improved high pressure metal vapor discharge tube of claim 1 wherein said wire extending through each aperture has a diameter of less than 2 mm.
Claim 5
Dependent Claim
21 words
The improved high pressure metal vapor discharge tube of claim 1 wherein said alumina end disks are constructed of opaque alumina.
Claim 6
Dependent Claim
43 words
The improved high pressure metal vapor discharge tube of claim 1 wherein each of said alumina end disks has a protrusion extending from one surface thereof, said protrusion being a centering guide and being fit in respective end openings of said tubular enclosure.
Claim 7
Dependent Claim
49 words
The improved high pressure metal vapor discharge tube of claim 1 wherein said at least one metal halide is a halide of a metal selected from the group consisting of the alkali metals, aluminum, the titanium group, the niobium group, the rare earth metal group and the actinoid group.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |